1. Field of the Invention
The present inventions generally relate to imaging technology such as wide-angle video, and more specifically to manipulating images or views within such imaging technology.
2. Description of Background Art
A new class of camera replaces the mechanical PTZ mechanisms by a wide-angle optical system and image processing as discussed in U.S. Provisional Applications 60/467,588, 60/467,644 and 60/467,705. This camera monitors a wide field of view and selects a plurality of regions from it to transmit to a base station either in analogue or digital form. In this way it emulates the behavior of a mechanical PTZ camera while also providing a full panoramic view for situational awareness. The wide-angle optics introduce distortion into the captured image, and an in-camera transformation engine is preferably used to correct the distortion and convert it to a view that has the same perspective as a mechanical PTZ camera.
A typical video surveillance environment will frequently contain moving objects such as pedestrians. A difficulty arises when an operator wishes to control the tilt of a PTZ camera to track an object that moves through a point directly below the camera. If the camera cannot automatically compensate for this occasion, then the output image will appear reversed as the camera tilts beyond the vertical position. The U.S. Pat. No. 5,627,616 discloses a camera comprising of an auto-pivot means for automatically rotating a mechanical PTZ camera about the pan axis by 180 degrees, hence enabling a moving object to be tracked without the image on the monitor being upside-down.
The present innovations present a system and method for implementing automatic pivoting functionality on a wide-angle video camera with electronic PTZ capability.
Automatic Pivoting in a Wide-Angle Video Camera
In one example, the present innovations are embodied as a wide-angle video camera system that automatically pivots at least a portion, or a modified portion, of a preferably wide-angle view under certain conditions. For example, in one preferred embodiment, a region of interest (RoI) is selected and tracked by an electronic PTZ capability of the wide-angle camera. If the RoI moves through a pre-determined course, (for example, if the center of the RoI is tilted through a direction which is perpendicular to the plane of the camera mounting), then the output image is automatically rotated by 180 degrees about an axis. In other embodiments, control circuitry temporarily reverses the interpretation of the tilt axis from the PTZ controls, thereby allowing the virtual view to tilt uninterrupted in the same direction past the auto-pivoting point.
These and other embodiments of the present innovations are described more fully below.
The disclosed innovations, in various embodiments, provide one or more of at least the following advantages:                Preferably has the effect of making an image that would otherwise be “up side down” from a human visual perspective to be “right side up;”        Smooth, uninterrupted movement past the auto-pivoting point;        Non-mechanical manipulation of a view requires fewer working parts;        Non-mechanical manipulation is faster than mechanical movement.        